Coin bank



FIG. 1 is a top plan view of a coin bank showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevational view thereof; and,

FIG. 6 is left side elevational view thereof.

The broken lines shown in the drawings represent portions of the coin bank that form no part of the claimed design. 

The ornamental design for a coin bank, as shown and described. 